JP2688354B2 - RDS receiver - Google Patents

Description

TECHNICAL FIELD The present invention relates to a receiver of a radio data system (hereinafter referred to as RDS).
Referred to as a receiver). BACKGROUND ART When a broadcast station broadcasts, broadcast-related information such as information related to the program content is transmitted as data by multiplex modulation, and a desired program content can be selected on the receiving side based on the demodulated data. Radio data system (RD)
S) there. In this radio data system, 57 kHz, which is the third harmonic of the 19 KHz stereo pilot signal outside the frequency band of the FM modulation wave, is used as a subcarrier, and the subcarrier is filtered and biphase-coded. The radio data signal is amplitude-modulated by a data signal indicating information related to the broadcast such as the content, and the amplitude-modulated subcarrier is frequency-modulated to the main carrier for broadcasting. A radio data signal has 104 bits of 1 as shown in FIG. 5 showing its baseband coding structure.
It is repeatedly multiplexed and transmitted as a group. One group is composed of four blocks each having a 26-bit configuration, and each block is composed of a 16-bit information word and a 10-bit check word. In FIG. 6, a block 1 broadcasts a program recognition (PI) code representing a network, a block 2 broadcasts a traffic program identification (TP) code or a traffic announcement identification (TA) code, and a block 3 broadcasts the same program. The station frequency (AF) data of the existing network station and the program service name information (PS) data such as the broadcast station name and the network name are arranged in the block 4. In addition, each group has 4 bits of type 0 to 15 according to its contents.
There are 16 distinctions, and two versions A and B are defined for each type (0 to 15), and these identification codes are arranged in block 2. In addition,
The AF data of the network station is transmitted only in the type 0A group, and the PS data is transmitted in the type 0A and 0B groups. On the other hand, in the type 3 group, related information of another network station different from the network of its own station is transmitted. Seventh
The figure shows the format of the type 3A group. The AF data of other network stations is placed in block 3 of the type 3A group, and the PI code and program number (PIN) are stored in block 4 as information related to other network stations. Code, TP code, program type (PTY) code, TA code, A
One of the F data is arranged according to the contents of the codes C ₁ and C ₀ of the block 2. The information of this block 4 is also transmitted to the block 4 of the type 3B group. Store address codes D ₂ , D ₁ and D ₀ of block 2 are provided to identify the type of another network that is transmitting in consideration of the fact that there are multiple different other networks. Information can be transmitted. By the way, when one RDS broadcast is received, it is possible to obtain the above-mentioned related information of other networks.
When selecting an RDS broadcasting station, it would be convenient if the related information of other networks could be used to tune in easily and in good reception. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to easily select a broadcasting station of a network different from the broadcasting station that is currently receiving by utilizing the related information of another network and in a good reception state. It is to provide a control method of the RDS receiver. An RDS receiver having a radio data control function of the present invention has at least one RDS receiver for each of a plurality of preset channels.
Equipped with preset memory to store one frequency data,
An RDS receiver having a radio data control function capable of preset tuning using frequency data stored in a preset memory, the demodulating means for demodulating a radio data signal from a broadcast wave being received, The frequency data relating to at least one other network different from the network to which the broadcasting station transmitting the medium broadcast wave belongs is read from the radio data signal, the preset memory corresponding to the other network is discriminated from a plurality of preset channels, and The present invention is characterized by including control means for storing frequency data regarding another network in a preset memory corresponding to the determined preset channel. Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the RDS receiver according to the present invention shown in FIG.
The FM multiplex broadcast wave received by the antenna 1 is selected by the front end 2 as a desired station, converted to an intermediate frequency (IF), and then supplied to the AF detector 4 via the IF amplifier 3. The front end 2 is composed of a PLL circuit and a mixer, and the local oscillator signal to the mixer is obtained by a PLL synthesizer method using a PLL circuit including a programmable frequency divider, and the frequency division ratio of the programmable frequency divider is A channel selection operation is performed by being controlled by a controller 14 described later. The detection output of the FM detector 4 is supplied to the MPX (multiplex) demodulation circuit 5, and in the case of stereo broadcasting, L
Separated into (left) and R (right) channel audio signals. When the detection output of the FM detector 4 passes through the filter 6, a 57 KHz subcarrier amplitude-modulated by the biphase-coded data signal, that is, a radio data signal is extracted and demodulated by the PLL circuit 7. . This demodulated output is supplied to a digital (D) PLL circuit 8 and a decoder 9.
Supplied to In the D-PLL circuit 8, a clock for data demodulation is generated based on the demodulated output of the PLL circuit 7. The generated clock is supplied to the gate circuit 10. The lock detection circuit 11 detects that the D-PLL circuit 8 has locked, generates a lock detection signal, and supplies this to the gate circuit 10 to control the circuit 10 to open. The lock detection signal is also supplied to the AND circuit 17 as a synchronization detection signal indicating that synchronized demodulated data is obtained. In the decoder 9, the bi-phase coded data signal, which is the demodulated output of the PLL circuit 7, is output to the D-PLL circuit 8.
It is decoded in synchronization with the clock generated in. As shown in FIG. 5, the output data of the decoder 9 is a 104-bit group unit consisting of 4 blocks of 26-bit structure, and is sequentially supplied to the group / block synchronization & error detection circuit 12. The group / block synchronization & error detection circuit 12 synchronizes the group with the block based on the 10-bit offset word assigned to the 10-bit check word of each block, and 16-bit information based on the check word. Word error detection is performed. Then, the error-detected data is supplied to the controller 14 after the error is corrected by the error correction circuit 13 at the next stage. The controller 14 is composed of a microcomputer, and code information of each block in the radio data that is sequentially input in units of groups, that is, radio data information related to the program content of the broadcasting station currently being received (the PI code and AF data described above). , PS data, etc.) and capture it in the memory 15. In addition, the selection is performed by controlling the reception frequency data value that determines the frequency division ratio of the programmable frequency divider (not shown) of the PLL circuit that forms a part of the front end 2 based on the tuning instruction from the operation unit 16. Perform station operation.
The reception frequency data value is, for example, the count value of the counter. The memory 15 is composed of a nonvolatile RAM in which data such as reception frequency data, PI code, AF data, etc. is written, and a ROM in which programs and data are written in advance.
This RAM has preset channel 1 as shown in Fig. 2.
A PI storage area for PI codes and a preset storage area for writing frequency data for eight stations are formed for each ch to 6 channels. For example, the PI code obtained from the input data can be written together with the frequency data in the preset mode when the RDS broadcast is being received in the PI storage area. Further, the operation unit 16 is provided with a plurality of operation buttons such as an auto preset button 23 for designating an auto preset operation and preset channel buttons “1” to “6” 25 for preset channel selection. In the PI code and AF data read from the data supplied from the error correction circuit 13 by operating the auto preset button 23, the PI code different for each preset channel and the AF data of the network station group represented by the PI code are stored in PI. It is written in each of the area and the preset storage area. When one of the preset channel buttons “1” to “6” 25 is operated, the controller 14 displays, for example, the data of the first station among the plurality of frequency data stored in order in the selected preset channel. Read and use as reception frequency data
Set it to the divider of the PLL circuit. When the same preset channel button 25 is operated again, the data of the second station of the plurality of frequency data is read and set as the received frequency data in the frequency divider of the PLL circuit, and the frequency data of eight stations is stored. If the same preset channel button 25 is operated 9 times, the cycle is cycled and the frequency data of the first station is read out again. Next, the operation of the processor of the controller 14 will be described with reference to the flow chart shown in FIG. When the processor finishes the tuning operation, that is,
When the receiving frequency is changed in the tuning operation to end the tuning operation, radio data obtained from the newly selected received broadcast wave is sequentially received through the error correction circuit 13 (step 51). , It is determined whether or not the received radio data is other network related information different from the network to which the station transmitting the current reception wave belongs (step
52). If the information is related to another network different from the network to which the station transmitting the current received wave belongs, the AF data of the other network station is read in block 3 (step 53). As shown in FIG. 7, since AF data for two stations can be included in one group, AF data for one or two stations on the same network can be read by transmission of one group. Next, it is judged whether or not the station number data n indicating the number of AF data is detected from the read AF data (step 54). As shown in FIG. 4, the AF data group of one network is the number of AF data transmitted at the head, that is, the station number data n (the number of broadcasting stations receivable around the data transmitting broadcasting station, up to 25 stations). ) Are arranged, and after that, the actual n frequency data f ₁
...... f _n is followed in the order close from the current received broadcast station position. Therefore, in step 54, the head of the AF data group of one network is detected by determining whether or not the station number data n indicating the AF data number is detected. If it is detected that the head of the AF data group of one network is detected, the flag F is set to 1 (step 55), and both the codes C ₁ and C ₀ included in the store address code in the block 2 are detected. It is determined whether both are 0 (step 56). On the other hand, if it is not the head of the AF data group of one network, it is judged whether or not the flag F is equal to 1 (step 57). If F ≠ 1, the current process is terminated, and if F = 1. Since the detection of the beginning of the AF data group has already been detected, the process proceeds to step 56. Where C ₁ = C ₀ =
The determination of 0 will be described. If C ₁ = C ₀ = 0, the PI code corresponding to the AF data of the other network read in step 53 is transmitted in block 4 as shown in FIG. Four
By reading the inside PI code (step 58), it is possible to know which PI code the AF data of the other network corresponds to. The flag F is initialized to 0 by the end of the tuning operation. Then, the variable m indicating the preset channel number is set equal to 1 (step 59), and the same PI code as the PI code read in step 58 is set in the preset channel m-.
Whether or not ch is allocated is determined from the PI code stored in m-ch in the PI storage area of the memory 15 (step 60). That is, the read PI code and memory 15
The identity with the PI code stored in the m-ch of the PI storage area is determined. When the read PI code is not assigned to the preset channel m-ch, 1 is added to the variable m (step 61), and as a result of the addition, it is determined whether or not the variable m is larger than 6 ( Step 62). m ≦
If it is 6, it means that all preset channels have not been identified, so return to step 60 and step
The process of determining the preset channel to which the PI code read in 58 is assigned is performed for the next preset channel number. If m> 6, it means that there is no preset channel to which the PI code read in step 58 is assigned, so the AF data read in step 53 is not written to the preset storage area. When the preset channel m-ch to which the PI code read in step 58 is assigned is searched (step 60
If YES), it is determined whether or not the AF data for 8 stations has been written in the preset storage area corresponding to the preset channel m-ch (step 63). If the AF data for 8 stations has not been written, The AF data read in step 53 is written as frequency data at an empty position where the frequency data in the preset storage area corresponding to the preset channel m-ch is not stored and can be written (step 64). If the frequency data for 8 stations has been written, the AF data read in step 53 is not written and the flag F is reset to 0 (step 6).
Five). Therefore, by repeating this operation, except for the network to which the station transmitting the current received wave obtained from the RDS broadcast wave newly received by the PI code stored and stored in the preset storage area corresponding to the preset channel belongs. It is possible to sequentially update the frequency data in the preset storage area to the latest one based on the AF data and PI code of another network. EFFECTS OF THE INVENTION As described above, in the receiver of the present invention, the frequency data of another network different from the network to which the broadcasting station that transmits the broadcast wave belongs is read from the received broadcast wave, The preset channel corresponding to the other network is discriminated, and the frequency data relating to the other network is stored in the preset memory corresponding to the discriminated preset channel. Therefore, in order to listen to the other program different from the program currently being listened to, the other network's When selecting a broadcasting station, it is possible to easily select a station by a preset tuning operation. Moreover, especially in the RDS system, since the broadcast frequency data is transmitted in the order of receivable broadcast stations in a close position centering on the position of the broadcast station transmitting the received broadcast wave, it is possible to obtain a good reception state by updating the data. Broadcast stations can always be preset.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of an RDS receiver according to the present invention, FIG. 2 is a diagram showing a preset storage area in a RAM, and FIG. 3 is a controller in the receiver shown in FIG. Fig. 4 is a flow chart showing the operation of the processor in Fig. 4, Fig. 4 is a diagram showing the format of AF data groups in one network, Fig. 5 is a diagram showing the baseband coding structure of radio data signals, and Fig. 6 is a type 0A group. And FIG. 7 is a diagram showing the format of the type 3A group. Description of symbols of main parts 1 ... Antenna 2 ... Front end, 4 ... FM detector 5 ... Multiplex demodulation circuit 8 ... Digital PLL circuit 9 ... Decoder, 14 ... Controller

Continuation of front page    (72) Inventor Toshito Ichikawa               Saitama Prefecture Kawagoe City Oji Yamada 25 Nishimachi 1               Pioneer Corporation Kawagoe Factory                (56) References JP-A-56-89123 (JP, A)                 JP 59-25430 (JP, A)                 Nikkei Electronics August 24, 1987               Japanese issue, pages 202-217

Claims (1)

(57) [Claims] An RDS receiver having a preset memory for storing at least one frequency data for each of a plurality of preset channels and having a control function by radio data capable of preset tuning using the frequency data stored in the preset memory. And demodulating means for demodulating a radio data signal from a broadcast wave being received, and frequency data relating to at least one other network different from the network to which the broadcast station receiving the broadcast wave being received belongs from the radio data signal. reading,
A control unit that determines a preset channel corresponding to the other network from the plurality of preset channels, and stores frequency data regarding the other network in the preset memory corresponding to the determined preset channel. RDS receiver with control function by radio data. 2. Each of the plurality of preset channels can store network type data specifying a network in association with frequency data relating to the other network, and the control means reads the network type data relating to the other network from the radio data, The RDS having a radio data control function according to claim 1, wherein the corresponding preset channel is determined based on the read network type data and the network type data stored in the preset memory. Receiving machine.